In action anti-aircraft and naval gunners or missile launchers have to be able to engage targets such as aircraft which approach from any bearing around 360.degree. to horizon and at any elevation over an arc of 180.degree.. In order to avoid the use of expensive targets, missiles and gun shells it has been conventional to train gunners or missile launchers in simulated attack conditions using target/gun and target/missile launcher simulators.
Conventional target apparatus for use in such training, has either a structure forming a hemispherical screen mounted on a cylindrical wall or a structure forming a screen of concave truncated spherical shape, in which structure a weapon can be placed. A fixed film projector is located within the structure to project a target image onto the screen provided by the structure interior, via one or more mirrors movable in response to a system of cams and wires or a system of servo-motors. Movement of the mirrors by the cams and control wires or servo-motor system provides movement over the screen of the target image projected by the fixed film projector.
Means are provided for predetermining, or calculating, and positioning on the screen a target image future position point along the flightpath of the target image in order to define the correct point of aim at each position of the target image on the screen. Customarily this is done by projection of an infra red beam of radiation onto the screen from a position adjacent the fixed film projector together with the provision on the weapon of an infra-red detector so that when the weapon sight is correctly aligned with the target image future position spot on the screen and the weapon trigger activated, a hit on the target image is recorded.
Such conventional target apparatus has three serious disadvantages. The first disadvantage is that the use of a fixed film projector, movable mirror or mirrors, cams and control wires or servo-motor systems with a hemispherical screen mounted on a cylindrical wall produces a target apparatus which cannot provide a target image at bearings around more than 200.degree. of horizon and at elevations of more than 108.degree. of arc. Similarly the use of a fixed film projector, movable mirror or mirrors, a system of cams and wires or a system of servo-motors with a structure forming a screen of concave truncated spherical shape produces a target apparatus which cannot provide a target image around more than 266.degree. of horizon and over an elevation of more than 108.degree. of arc. This is a particularly severe disadvantage as it does not enable conventional target apparatus to provide realistic training conditions necessary to engage and destroy targets approaching at bearings and elevations falling within the area of the dead sector necessarily produced by these conventional forms of target apparatus. Conventionally the weapon is placed in the dead sector in such structures.
The second disadvantage is that such conventional target apparatus are only able to provide in the same scene a single target image or multiple target images which always move as one, and this cannot provide effective training to cope with the modern ground attack aircraft tactics of flying in pairs with one aircraft approaching the target area from one direction to engage ground defences while the other completes the attack run from another direction. Similar tactics are also employed by modern naval fast patrol/missile launch vessels.
The third disadvantage is that by the use of an infra-red target image future position projector on or near the target image projector and an associated infra-red detector on the weapon sight it was difficult and complicated to provide anything other than a target hit or a target miss indication. No miss distance indication was provided if the weapon was not aimed correctly when the trigger was activated and indeed no indication could be given of the projectile flightpath position on the screen.
A target apparatus has been proposed by the present applicants which includes a structure forming a screen of concave truncated spherical shape in which a weapon can be placed, at least one target image projector mounted for universal movement within the structure for projecting a target image onto the screen, an infra-red projector for projecting a beam of radiation onto the screen at a selected position relative to the projected target image, which selected position corresponds to the position at which the weapon should be aimed to produce a hit on the target image when fired, an infra-red detector means movable with the weapon for registering a hit or miss by detecting whether or not the weapon is aimed at the selected position when fired and a laser projector mounted with the target image projector and the infra-red projector for selective operation to provide a visual indication on the screen only of the selected position produced by the projected infra-red radiation beam. Optionally with this proposed target apparatus there may be more than one target image projector.
Although the foregoing proposed target apparatus alleviates the first disadvantage by the provision of a universally movable target image projector and alleviates the second disadvantage by the provision on a vertical line through the center of curvature of the concave truncated spherical shape screen of one or more universally movable target image projectors it does not alleviate the third disadvantage.